Apparatus for making powdered metals



Patented May 12, 1936 UNITED STATES PATENT OFFICE APPARATUS FOR MAKINGPOWDERED METALS This invention relates to improvements in powderedmetals, and more particularly to an improved method and apparatus formaking same.

With the advent of present day developments in forming metallicstructures directly from the powdered components without theintervention of fusing and casting steps, a simple; efficient andreliable process for the preparation of the powdered metalliccomponentshas beensought.

Itis an object of this invention to provide an improved process for thepreparation of powdered metals.

It is a further object of this invention to provide such an improvedprocess in which molten metals are dissipated and atomized into a bodyof cooling fluids.

Yet another object of this invention is the provision of such animproved process in which the molten metal is scattered integrally andin droplet form into a body of cooling fluid.

It is also an object of this invention to provide improved apparatus forforming powdered metals.

These and other desirable objects and advantages of the presentinvention will be described in the accompanying specification andillustrated ,in the drawing, forming a part thereof, certain apparatusfor carrying out the process of the invention being shown by way ofillustration only, for, since the underlying principles may beincorporated in other specific mechanical constructions, it is notintended to be limited to the ones here shown, except as suchlimitations are clearly imposed by the appended claims.

In the drawing, like numerals refer to similar parts throughout theseveral views, of which Fig. 1 is a vertical elevation of a centrifugalapparatus, an associated driving motor and pouring funnelor spout beingshown in elevation,'and

Fig. 2 is a vertical section through an apparatus showing thecentrifugal members disposed within a tank of fluid, the pouring funnelor spout and driving motor being shown in elevation.

Referring more specifically to the drawing, the construction shown inFig. 1 comprises, generally, a reaction chamber or container I!) mountedfor rotation on and about the axis II of a motor l2 which is suitablysecured to and supported upon a supporting member, indicated generallyat [3. Any suitable means of securing the motor 12 to the support [3 maybe made use of and will not be described further as the specific meanscontemplated forms no part of the present invention other than in thecombination shown. A pouring funnel or spout M of any desired shape mayserve to introduce the molten metal into the member l during the castingoperation.

The member l0 comprises, generally, a bottom or base plate ii, of anysuitableheatresisting composition, and of any desired thickness andshape. 5 To this base is secured, in any desired manner, a rim memberl6, generally of semi-circular configuration. The member l5, as alreadyindicated,

may be made of any suitable heat resisting material, such as magnesite,and is secured to the shaft H in a suitable manner and centrallythereof. The rim l6 may be made of thin metal and is preferably providedwith an interior facing of heat resisting material I! which may be ofmagnesite or any other such material rammed in place and thereafterbaked.

The rim IS with its associated heat resisting liner I! is curvedinwardly at its free edge, indicated generally at l8, to provide atrough l9 which serves as a retaining member for material forced thereinupon rotation of the member l5 about its axis. A body of water, 20, maybe introduced into the bottom of the chamber l0 and when the member IDis in a state of rest will fill the bottom thereof to a desired height,indicated generally at 2!. Upon rotation of the member I the water 20will be thrown outwardly into the channel l9 and will form a ring ofcooling fluid 22 coextensive with the retaining channel members andconfigured thereto.

In operation the metal, alloy, or other composition to be powdered isprojected upon the rotating plate l5, at the axis thereof, by means ofthe spout or nozzle of the pouring device H. The particles of the moltenmaterial impinge upon plate l5, at the axis thereof, and are flattenedand simultaneously projected outwardly because of the centrifugal effectof the whirling disc l5.

In this operation the material is effectively broken up into minuteparticles, which upon striking the body of the liquid 22 in the channell9, are immediately cooled. By varying the distance from the outlet endof the nozzle or pouring spout I4 to the plate l5, and by varying thepressure with which .the molten metallic material is projectedtherethrough, any desired particle size may be imparted to the moltenmaterial, as it will be readily apparent that with a slow flow of moltenmaterial with a low hydrostatic head, larger particles will be formedthan will be the case where a stream of material under a relativelygreater hydrostatic head is projected against the plate through agreater distance. This very desirable variation in particle size may beof particular advantage in the treatment of 5 different metalliccompositions where the reactions may be dependent upon the particlesize, and differential reactions may be controlled by suitablycontrolling the particle size of the materials used.

With the use of water for a cooling fluid, readily oxidizable metals,such as iron and the like, will be formed in particles having aprotective oxidized coat of the oxide formed on the surface thereof.Owing to the speed of cooling from the molten to the solid particulatestate, the oxide,

coating formed will be of substantially infinite thinness and can laterbe readily removed by heating to low red heat in the presence of anatmosphere of hydrogen, hydrocarbon gases and/or any other suitable anddesirable reducing material.

While water has been disclosed as a preferred cooling fluid, it will, ofcourse, be appreciated that a fluid having reducing qualities, in and ofitself, may be used. Thus, for example, the fluids used may comprise amixture of alcohol and water which will serve to reduce any oxidecoating formed and which is particularly suited for use with certain ofthe non-ferrous metals and for alloys such as nickel, copper and thelike.

The invention also comprehends the use of cooling fluids made up ofemulsions or suspensions of reducing materials in water, to minirnizeany tendency of the atomized metals, alloys, and metallic compoundsgenerally used to become oxidized. In addition, the chamber or spaceformed by the member in may be protected by a suitable inert ornon-reactive atmosphere, such as nitrogen and the like, and the tendencyto form undesired coatings on the atomized metal particles therebyminimized or avoided.

Upon completion of the run, the powdered metal will be removed from thebasket I and purified, if found necessary, in any desired mannet, andthereafter used as desired, and more particularly in the processes setforth and described in my prior application, Serial No. 593,883, filedFebruary 8, 1932.

The apparatus just described may be used for general work and. thebasket or revolving container It may be constructed in any desired size,according to the quantity of material to be treated. The motor andassociated apparatus will be suitably varied to take care of thecontainer and the quantity of material to be handled therein.

Where any great quantity of powdered metallic material is to be made useof, an apparatus of the type shown in Fig. 2 may be found to givedesirable results and meet the requirements for bulk operation. Thisdevice comprises generally a retaining tank or member having side walls30 of any suitable configuration and an outwardly sloping bottom 3|terminating inwardly in a central upstanding tubular member 32 whose topis peened over to form a, dome 33 having a central aperture 34. In thewell or chamber 35 formed by the member 32 a motor 36 is disposed and ismounted on a bushing or bearing 31, the latter in turn being mounted ona support 38 which also serves as a support for the tank 30. The motoris provided with the usual shaft H upon which is axially mounted a plate[a of any suitable dimensions. A bushing 39 having a flange 40 isdisposed over the shaft l l and abutted against the rim 34 of the dome33, a gland or washer 4| being fitted thereagainst from the other sideof the dome and being so configured and arranged as to hold the shaft Iirigidly against the inner periphery 34 of the dome. A

suitable pouring device having a spout Ha aligned with the axis of therotatable plate l5a is provided.

A body of cooling fluid 50 is disposed within the tank and preferably insuch an amount that its upper level 5| is disposed above the level ofthe plate I 5a.

Upon rotation of the plate i511 the water disposed thereabove will beforced by centrifugal action towards the edges of the tank forming. ameniscus 52 whose upper edge attains a height indicated generally by thelevel 53. To increase the body of the cooling fluid 52 the plate 15a andthe motor may be lowered by means of a shaft 31a, controlled by anysuitable mechanism, not shown, the glands 4| preventing leakage ofliquid past the motor shaft I I. Outlets 60 may be provided about thebottom periphery of the tank, in any desired manner, and may be providedwith closures SI of any desired type. They may be screw members asshown, or they may comprise gate valves of any desired construction.

The cooling fluid 50 may be composed of water, as indicated above, orany water solution, suspension or emulsion. It may also be composed ofany non-inflammable reducing liquid, and if a flammable reducingliquid,such as ligroin, kerosene and any other inorganic or organic medium beused, the space above the level of the liquid in the tank or containermay be filled with a non-oxidizing, protective inert and/or reducing gassuch as nitrogen, carbon dioxide,

hydrogen, carbon monoxide and the like.

It will now be appreciated that by the practice of the principles of thepresent invention, powdered metallic compositions may be made in anyquantity by impinging a molten stream of metal upon the axis of a.rotating member which is so configured and arranged that the particulatemetal scattered therefrom is immediately contacted with a body of acooling fluid, which may also include reducing elements, or be itselfboth a cooling fluid and a reducing-agent. The apparatus designed foruse with the improved process may be of a variety of types, each ofwhich is simple in construction and economical to manufacture andoperate, while at the same time providing for the production of desiredquantitles of powdered metallic compositions simply, efliciently and atvery low cost.

The powdered metals so prepared may be subjected to the action ofa'gaseous or vaporous reducing agent, before being used, in order toreduce any oxide or other coating formed on the surface of the metalparticles.

The particle size of the materials formed may be varied by varying anyor all of the following factors: The rate of flow of the material ontothe rotating disc; the speed of rotation of the disintegrating disc, andthe distance between the nozzle of the pouring spout and the facing ofthe disc. The greater the distance therebetween, the greater the drop ofthe metal and the finer the particles formed therefrom.

While the foregoing description has been set forth in general and indetail in respect to specific ideas, it will be understood that changesand modifications may be made therein and that such changes andmodifications are to be considered within the scope of the invention asdefined in the subjoined claims.

What is claimed is:

1. An improved apparatus for use in making powdered metals, comprising,in combination, a container for molten material, a plate upon .incombination, a plate of substantial thickness mounted for rotation aboutan axis, a peripheral channel member of relatively thin materialdisposed around the said plate and secured thereto, and a liner of heatresistant material formed within the said channel, the thickness'of thesaid liner and channel approximating that of the said plate.

3. An apparatus for forming powdered metal compositions, comprising, incombination, means for supplying molten material, a subjacent containerhaving side walls and an integral bottom, a recessed portion in saidbottom forming a well, a motor and associated supports mounted in thewell, a shaft in the motor extending through and slidably associatedwith the well, a plate mounted for rotation on the end of the shaft anddisposed within said container, and

a body of liquid in the container normally extending above the top ofsaid plate, and a peripheral restraining means for the liquidcooperating with said plate to form therewith a liquid meniscus which israised above the level of, the plate and is rotated therewith when theplate is roated.

4. An apparatus for forming powdered metals from a fused mass thereof,which comprises means to project the fused metal upon a rotatablemember, means to confine a body of liquid in contact with the rotatablemember and having a normal level above the upper surface of therotatable member, and means to rotate the rotatable member to effectcentrifugal displacenient of the body of liquid whereby to form ameniscus of the same in contact and rotatable with the said rotatablemember and disaggregation of the fused metal into particulate form whenprojected by the rotating member into the so-formed meniscus.

5. An apparatus for forming powdered metals from a fused'mass thereof,comprising, in combination, a container for the fused material, anoutlet for the said container, a receptacle subjacent to the containerand containing a body of cooling liquid therein, a plate mounted forrotation and disposed within the liquid in the receptacle, means forrotating the plate to thereby whirl the liquid and form a meniscus ofthe liquid rotatable by and with the rotating plate for quenching thefused material when projected outwardly from the rotating plate; andperipheral restraining means for the liquid cooperating with said plateto form therewith a liquid meniscus which is caused to rise above thelevel 01' the plate when the latter is rotated.

JEAN HUBER'I' LOUIS DE BATS.v

